Economic maximization of alfalfa medically-active phytoconstituents

Abstract

Medicinal plants are leading source of phytochemicals. A pot experiment was designed to evaluate the effect of various water regimes (33, 67 and 100% watering) on the ability of alfalfa plants grown in soils with different texture (33, 67 and 100% sand) to synthesize phenolics, non-photosynthetic pigments, vitamins and minerals. Under drought, the amount of total phenols, saponins, tannins, flavonoids and alkaloids increased with the maximum content of total phenols, tannins and flavonoids recorded for plants in soil with 67% sand. For saponins, 33% sand caused the highest values, while alkaloids increased with increasing sand proportion. Water stress also increased the amount of anthocyanins, lycopene and β-carotene. With adequate irrigation, soil with 33% sand caused the highest amount of these pigments while under drought; their values fluctuated among the three soil types. Moreover, the amount of vitamin C, B1 and B2 increased under water deficit; and their amount increased with increasing sand. Furthermore, the amount of sodium, potassium and calcium increased with drought; while the reverse was recorded for magnesium and phosphorus with the maximum titers of all the addressed elements in plants grown in 100% sand. Thence, little water availability may be an efficient technique invigorating alfalfa medicinal efficacy.